Minimizing the flight costs for given atmospheric conditions, cost index and flight distances may include obtaining the optimum Mach number for a given altitude. Generally the given altitude is provided by an Air Traffic Control (ATC) entity. Present solutions for optimizing aircraft flight costs are mainly focused on aircraft preliminary design instead of actual flight management system (FMS) implementation or trajectory prediction. These solutions contain significant simplifications such as ignoring factors (e.g., wind, parabolic drag polar, and constant thrust specific fuel consumption (TSFC)), that make the results inappropriate for the operational use thereof. Even if wind is considered, conventional solutions apply wind as a correction after obtaining an optimum Mach number for a zero wind condition.